New ESC guidelines on hypertrophic cardiomyopathy: new insights in invasive treatment?

The Diagnosis and Treatment of Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) with or without left ventricular outflow tract (LVOT) obstruction is a common primary myocardial disease, with a prevalence of 1:500. It is characterized by thickening of the myocardium. Its diagnostic evaluation includes history-taking and physical examination, genetic studies, transthoracic echocardiography, and cardiac MRI. When optimally treated, it carries a mortality of less than 1% per year.

METHODS

This review is based on pertinent publications retrieved by a selective literature search, including the current guidelines.

RESULTS

In symptomatic patients with high LVOT gradients (≥ 50 mm Hg), the treatment of first choice is pharmacotherapy with nonvasodilating beta-blockers or non-dihydropyridine-type calcium channel antagonists. Common side effects include bradycardia and hypotension, and there is a risk of AV nodal blockade. Both substance classes lower the LVOT gradient. Beta-blockers alleviate dyspnea and improve patients' quality of life. Verapamil can increase physical resilience. A further option is mavacamten, a myosin inhibitor that gained approval in Germany in mid-2023: it, too, lowers the LVOT gradient and improves quality of life. In 7-10% of patients, there is a reversible reduction of the left ventricular ejection fraction to less than 50%. Septal reduction treatments can be considered if drug therapy fails. Attention must also be paid to the management of sequelae such as atrial fibrillation, malignant arrhythmias, and mitral valve insufficiency.

CONCLUSION

Patients with HCM have a near-normal life expectancy if the disease is diagnosed early and treated according to the guidelines. The treatment of HCM and HOCM (hypertrophic obstructive cardiomyopathy) have been studied in no more than a few clinical trials, and randomized studies with clinical endpoints are needed.

Alcohol septal ablation in hypertrophic cardiomyopathy: For which patients?

Percutaneous and surgical therapies for septal reduction for hypertrophic cardiomyopathy have been going head-to-head for the past 20 years with similar outcomes and mortality rates, although contemporary myectomy seems to materialize its superiority. However, on closer analysis, the external validity of studies advocating myectomy does not translate to all centres. The aim of this review was to examine the most recent data on septal reduction therapy and to attempt to phenotype the appropriate patient for each of the two treatments. The key to similar low mortality rates between ventricular septal myectomy and alcohol septal ablation appears to be proper patient selection performed in high volume clinical environments. Furthermore, we analyse the role of mavacampten (the recently approved cardiac myosin inhibitor) in replacing or complementing the two septal reduction therapies.

Life-long tailoring of management for patients with hypertrophic cardiomyopathy : Awareness and decision-making in changing scenarios

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, characterised by complex pathophysiology and extensive genetic and clinical heterogeneity. In most patients, HCM is caused by mutations in cardiac sarcomere protein genes and inherited as an autosomal dominant trait. The clinical phenotype ranges from severe presentations at a young age to lack of left ventricular hypertrophy in genotype-positive individuals. No preventative treatment is available as the sequence and causality of the pathomechanisms that initiate and exacerbate HCM are unknown. Sudden cardiac death and end-stage heart failure are devastating expressions of this disease. Contemporary management including surgical myectomy and implantable cardiac defibrillators has shown significant impact on long-term prognosis. However, timely recognition of specific scenarios - including transition to the end-stage phase - may be challenging due to limited awareness of the progression patterns of HCM. This in turn may lead to missed therapeutic opportunities. To illustrate these difficulties, we describe two HCM patients who progressed from the typical hyperdynamic stage of asymmetric septal thickening to end-stage heart failure with severely reduced ejection fraction. We highlight the different stages of this complex inherited cardiomyopathy based on the clinical staging proposed by Olivotto and colleagues. In this way, we aim to provide a practical guide for clinicians and hope to increase awareness for this common form of cardiac disease.